staging: skein: remove extra indentation

Fix macros containing do/while blocks to be indented uniformly.

This patch fixes the checkpatch.pl warning:

WARNING: suspect code indent for conditional statements
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>